Demonstrating device



Feb. 7, 1933. R. w. BROWN DEMONSTRATING DEVICE Filed July 27, 1931 INVENIVTOR 3.011 W. Brown ATTORNEYS Patented Feb. 7, 1933 I UNITED STATES. mum:eme y 7 noYw. BROWN, or AKRON, onro, AssrGnon TO THE nrnns'ronn Tim: at RUBBER coma PANY, 0F AKRON, OHIO, A- GORPORATIONOF OHIO nnmons'rnn'rme nnvrcn Application filed. July 27,

This invention relates to demonstrating devices, and more especially it relates to devices for visibly demonstrating the fsuperi ority of rubber asa medium for dumping or absorbing the vibrations of a vibrating body. The superiority of rubber as a'vibra tion' dampener is demonstrated, in the device constituting this invention, by 'the use of metal in the same relative position "as the rubber, so that the relative merits of thetivo materials readily maybe demonstrated. The chief objects of the invention a're'to provide a simple and compact device for demonstrating the ability of rubber to absorb vibrations; and to demonstrate the relative merits of metal and rubber asa means for supporting vibrating bodies. Other objects will be manifest.

Of the accompanying drawing: Figure 1 is a side elevation of a device embodying the invention, in its'preferred form; Figure 2 is a section on the line 2-2 of Figure 1; and i Figure 3 is a section on the line 33 of Figure 1.

Referringto the drawing, there is shown a relatively small, portable electric motor 10 which may be of standard construction, but preferably is provided with'an unbalanced rotor so as to vibrate excessively when driven. The unbalanced condition of the rotor may be effected in any suitable manner, one way being shown in Figure 2 whereina small piece of metal 11' such as solder is secured to the periphery of the armature 12 of the motor. The motor isprovided with the usual conductor cord 13 by which is may be attached to any convenient electrical outlet.

The motor is arranged to rotate on a vertical axis and to this end provided with respective base members 14, 15which may be of wood, said base membersbeing ident1cal in size and shape, and disposed'concentrically of the motor at opposite ends thereof) The base member 14- is secured to the motor 10 by a plurality of connectors 16, 16, herein shown as three, which are symmetrically arranged about the axis of the motor. Each coupling 16 comprises a cylindrical block of resilient rubber 17 that has a short threaded stud 18 5 1931'. seared. 553,324.

secured to one ofits ends and threaded'linto thecasing of the motor"10',and has a stud bolt 19 secured to its opposite end and at i tached to the base member 14 by a nut20. 1 Y

Theermn ement is such that the motor is insulated from the base member 1 1' by re- .sllie'nt r bber.

*Atthe oppositeend ofthe' device the base i member- 15' is attached to the motor by a plumay of connectors 21,21 preferably of "the same'inumber, size, andmshap'e as=thef con nectors16, but composed entirely of metal.

so as to constitute a rigid connection between the motor and base memberl5y The operation of the device consists inconne'cting the motorto a suitable source of power to drive it, and then positioning it first on one base member and then on the other. The unbalanced condition of the ro- V tor of the motor causes thelatter to vibrate excessively, and when the motor is positioned upon the member 15 as a base the vibration is transmitted through the connectors 21 to the base with the result that the device creeps along the surface upon which it is bration of the motor substantially is ab.- sorbed or damped out by the rubber blocks 17 so that little or no vibration is transmitted to the base member 14, with the result" that the device remains stationary;

The device is'of simple construction, may be small enough to be readily portable, and

it clearly demonstrates the ability of rubber 1. A demonstrating devlcc comprising a" vibratory body, and a rigid and a resilient '1 placed When the devioe is reversed so as V to utilize the member 14 as a base, the vigop support secured to said body upon which it maybe alternatively positioned.

2. A demonstrating device comprising an unbalanced rotary member, and. a rigid and a resilient support upon which said member maybe alternatively positioned.

3. A demonstrating device comprising an electric motor having an unbalanced rotor,

and a rigid and a resilient structure adapted alternatively to support the motor on a vertical axis. i I

4. A demonstrating device comprising a vibratory electric motor, base'members at 0pposite ends thereof upon which the motor may be alternatively supported, a rigid connecing an unbalanced rotor arranged to rotate upon a vertical axis, base members at goppo tion between the motor and one base memher," and a rubber connection between the motor and the other base member;

5. In adevice of the character described, the combination of an electric motor havsite ends thereof upon whichtheflmotor is alternatively supported, a plurality of rigid onn ym rie lly ar an d ab u the axisof the motor at one end thereof onnec g e mot r t 6 ba member,

v and a plurality of similarly arrangedresilr ient connections at the other end of the mo- 7 tor connecting it to the other base member.

' of said axis upon which said 10taiy'n1ern f 6. Ina device of the.character'deseribed, t e co binat on of n unbfl anc drote member having. a vertical axis, and a resilt n a rig d supp r t the e p e ends ber alternatively ispositioned.

In witness whereof I have nor BROWN he e-ante, fixed my signat t 21st ay f uly, 1931. 

